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Biocatalyst development and production

Natural enzymes are evolved to meet the conditions of their habitats, and not the exact conditions of an industrial process. The multitude of microorganisms, living and thriving at the most different environmental conditions, has left us with a large tool-box of alternative biocatalysts that can be isolated from microbial strains or directly from the genetic material from environmental (enriched) samples. Despite this, for some processes, the naturally known alternative does not seem to be enough, and in vitro development (site-directed, or random), appears as an attractive solution. At the Dept. Biotechnology we have a long tradition in research and use of extremophilic enzymes (originating e.g. from microorganisms growing at high temperature, high pH or high salt). These are frequently used as our scaffolds for development. Two processes are selected for biocatalyst development and include synthesis of epoxides, and synthesis of alkylglycosides. Selected enzymes are produced as recombinant proteins.

Epoxide synthesis:

  • Lipase B, from Candida antarctica is investigated at molecular level
  • Novel enzyme groups are taken into account, including oxidative enzymes like monooxygenases, and for the production of chiral epoxides, epoxide hydrolases.

Alkyl glucoside synthesis:

  • Glycoside hydrolases (GH), traditional industrial enzymes that do not require cofactors for activity, are screened for synthesis possibilities (e.g. beta-glucosidase from Thermotoga neapolitana identified as an enzyme efficient in transglycosylation or reverse hydrolysis)
  • Selected candidates are chosen for development
  • Investigations of residues important for e.g. synthesis-ratio and substrate selectivity are ongoing (using mutagenesis and structure-function analysis)

A screening assay for selection of GH catalysing reverse hydrolysis is developed

Project leaders: Rajni Hatti-Kaul and Eva Nordberg Karlsson